This invention relates to radio communication systems, and more particularly to underwater radio communication systems which provide a submerged operator the capability to engage in two-way oral communications with a station on the surface.
Small, maneuverable underwater vehicles manned by operators with scuba support systems are in extensive use by the Navy for portage and delivery of personnel and equipment. Such craft are normally transported to a deployment site on a surface control craft, placed in the water, and submerged and operated in the vicinity of the surface craft. Command control of such vehicles by the surface craft is desirable from the standpoints of operational safety and effectiveness. A two-way communication link is necessary to effect the command and control capability.
Communication links which satisfy this objective have been provided either through a direct umbilical link between the surface and submerged crafts or through a sonar link. The tethered, umbilical link limits the range and maneuverability of the undersea vehicle as does the directionality of the sonar link. A two-way communication link utilizing radio broadcast techniques is obviously desirable from the standpoint of enhancing the freedom of movement of the undersea vehicle as well as providing omni-directionality to the communication link.